Topological susceptibility in 2+1-flavor QCD with chiral fermions

¹ Center for Gravitational Physics, Yukawa Institute for Theoretical Physics, Kyoto 606-8502, JAPAN
² School of Physics and Astronomy, The University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
³ Department of Physics, Osaka University, Toyonaka 560-0043, Japan
⁴ KEK Theory Center, High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801, Japan
⁵ School of High Energy Accelerator Science, The Graduate University for Advanced Studies (Sokendai), Tsukuba 305-0801, Japan

^* Speaker, e-mail: hfukaya[at]het.phys.sci.osaka-u.ac.jp

Published online: 26 March 2018

Abstract

We compute the topological susceptibility X_t of 2+1-flavor lattice QCD with dynamical Möbius domain-wall fermions, whose residual mass is kept at 1 MeV or smaller. In our analysis, we focus on the fluctuation of the topological charge density in a “slab” sub-volume of the simulated lattice, as proposed by Bietenholz et al. The quark mass dependence of our results agrees well with the prediction of the chiral perturbation theory, from which the chiral condensate is extracted. Combining the results for the pion mass M_π and decay constant F_π, we obtain X_t = 0.227(02)(11)M²_πF²_π at the physical point, where the first error is statistical and the second is systematic.